东北大西洋北海渔场鱼类群落结构年际变化研究

根据2001-2015年东北大西洋北海渔场进行的国际底拖网调查渔获数据，采用生物多样性指数和多元统计分析研究该海域群落结构的年际变化，并利用格局转变贯序t检验的方法研究鱼类种群的转变规律，结合环境因素与捕捞因素分析群落结构变化的原因。结果显示:2001-2015年北海渔场共出现280种渔业资源，其中鱼类有222种，资源丰度波动较大；物种多样性整体呈上升趋势。聚类分析和非度量多维标度排序分析表明，研究期间大致分为2001-2003年、2004-2011年和2012-2015年3个阶段。大西洋鲱分别在2004年和2014年种群结构发生格局转变，格局转变指数（RSI）分别为-0.45和0.41；黑线鳕在2003年和2012年格局发生转变，RSI值分别为-0.58和-0.66；黍鲱在2014年格局发生转变，RSI值为2。通过对环境因素与捕捞因素的分析发现，北海渔场群落格局第一次发生转变主要受捕捞因素影响，第二次发生转变主要受环境因素影响。

Study on the interannual variations in community structure in the North Sea of northeast Atlantic

Based on the data collected from the International Bottom Trawl Surveys in the North Sea from 2001 to 2015,multivariate statistical analysis and other integrated indices are used to analyze the variation in the community structure of fish assemblage over time in the waters.The regime shift of fish population are also studied by the sequential t-test analysis of regime shifts (STARS). The analysis of the change in community structure is also conducted based on the factors of environment and fishing. The results show that 280 species had been caught, 222 of which are fish species. The abundance varies dramatically annually. Diversity has a general uptrend. Cluster and MDS show that the fifteen years could be divided into three groups of 2001-2003, 2004-2011 and 2012-2015. STARS of Discriminating species shows that there are two regime shift of the Atlantic herring in 2004 and 2014, which regime shift indexes (RSIs) are -0.45 and 0.41. There are two regime shifts of the haddock in 2003 and 2012, which RSIs are -0.58 and -0.66. There is one regime shift of the sprat in 2014, which RSI is 2. Through the analysis of environmental factors and fishing factors, we find that the first change of community structure is mainly affected by fishing factors. The second change of community structure is mainly affected by environmental factors.